Trimmers on an Audio Interface mk1

There are 2 trimmers on my mark 1 Audio Interface, from a casual glance it looks as though they might be used to calibrate the input gain knobs. Is that right? I’d like to get the knob positions on each channel to match.

From the looks they’re Bourns 3362s (single turn trimpots).

Any tips? Any danger in changing them while powered up?